1. Field of the Invention
The present invention relates to a head support mechanism for supporting a magnetic head slider that includes a thin-film magnetic head, to a magnetic head assembly with the head support mechanism, and to a magnetic disk drive apparatus with the magnetic head assembly.
2. Description of the Related Art
In a hard disk drive (HDD) apparatus, thin-film magnetic head elements for writing or recording magnetic information into and/or reading or reproducing magnetic information from magnetic disks are in general formed on magnetic head sliders flying in operation above the rotating magnetic disks. The sliders are supported at top end sections of head support mechanisms configured by suspensions or support arms, respectively.
Recently, such HDD apparatus is assembled not only in a personal computer but also in a mobile equipment such as for example a portable digital audio player, a digital video camera, a mobile phone, a car navigation apparatus and other mobile gear. In order to assemble in the mobile equipment, required is increased recording and reproducing density to satisfy further miniaturization and higher data storage capacities of the HDD apparatus. This requirement in the increased recording and reproducing density accelerates miniaturization in the magnetic head element and lower flying height of the magnetic head slider.
On the other hand, for assembling in the mobile equipment, the HDD apparatus is required to endure a hostile environment in temperature, particularly in low temperature. More concretely, the HDD apparatus to be mounted in the mobile equipment is required to operate in environment conditions of low temperature of about to −30° C. or −40° C. that is extremely lower than the environment conditions of −10° C. for a general HDD apparatus.
A head suspension assembly of the HDD apparatus is in general assembled by adhering using a resin adhesive a magnetic head slider to a suspension having a thermal expansion coefficient different from that of the magnetic head slider. Therefore, a crown amount of the magnetic head slider changes depending upon change in its temperature environment due to the thermal expansion coefficient difference. Particularly, under the low temperature environment, because the thermal expansion coefficient of the suspension is larger than that of the magnetic head slider, a compression force will be applied to the magnetic head slider from the suspension to produce crown deformation of the slider.
FIGS. 1a and 1b provide an explanation of crown deformation of a magnetic head slider under a low temperature environment according to the conventional art. FIG. 1a illustrates the state of a head suspension assembly under an ordinary temperature environment, and FIG. 1b illustrates the state of the head suspension assembly under an extremely low temperature environment.
As shown in FIG. 1a, under the ordinary temperature environment, no thermal effect on a tongue portion 10 of a flexure and on a magnetic head slider 12 fixed to the flexure by a resin adhesive 11 occurs, and therefore no compression force is applied from the flexure to the slider 12. However, under the extremely low temperature environment, as shown in FIG. 1b, because the tongue portion 10 of the flexure deforms or compressed larger than the magnetic head slider 12, occurred is a crown deformation of the slider, that is, a deformation for moving the trailing edge and the leading edge of the slider away from the surface of a magnetic disk 13 to which the slider faced. If such crown deformation occurs, a spacing between a write and read magnetic head element 14 and the surface of the magnetic disk 13 increases to greatly decrease the write and read characteristics of the magnetic head elements.
U.S. Pat. No. 6,950,266 discloses a flying height control method for a magnetic head slider in which a piezoelectric actuator is inserted between a tongue portion of a flexure and the magnetic head slider so as to compensate the crown deformation of the slider.
However, according to this known method described in U.S. Pat. No. 6,950,266, the structure of a magnetic head assembly becomes complicate and, due to insertion of the piezoelectric actuator having a significant thickness between the tongue portion and the slider, the design and fabrication of the magnetic head assembly become difficult to increase the manufacturing cost. Further, the control method of the piezoelectric actuator for compensating the crown deformation of the slider also becomes complicate.